Such a carding machine is known e.g. from German-Offenlegungsschrift 2 226 914. The carding segments described there have different tooth densities per unit area.
Such devices serve to clean, open and parallelize raw fibres, e.g. cotton. The starting material (in the form of flocks) is supplied via an opening cylinder unit to a cylinder (e.g. a main cylinder) provided with a lining, and entrained by the circumference of said cylinder in the direction of rotation. For this purpose, the cylinder is provided with a large number of sawteeth. Normally, this toothed lining is formed by producing a sawtooth wire which is then wound onto the outer circumference of the cylinder. The tooth shapes can be designed differently for a great variety of different applications. The tips of the teeth, however, point mainly in the direction of rotation.
Carding segments are arranged at least over part of the circumference of the cylinder so that the fibres are not only entrained by the cylinder provided with a lining but also subjected to processing. Normally, a carding segment will extend over the whole width of the cylinder. The lower surface of a carding segment has an arcuate shape, whereby it is adapted to the outer circumference of the cylinder provided with a lining, and it is also equipped with a toothed lining. In many cases, the teeth are arranged in rows of teeth one behind the other and are also produced by insertion of a sawtooth wire. The tooth shape is similar to the shape of the teeth on the cylinder provided with a lining, the tips of the teeth pointing in a direction opposite to the direction of rotation of the cylinder provided with a lining. The carding segments are moved so close to the cylinder that the fibres are subjected to an opening, combing and parallelization process.
Between the carding segments, cleaning stations can be arranged, which are provided with suction means for removing dirt particles and fibre fragments. This means that the carding segments may also be arranged at a certain distance from one another. This kind of device for treating fibre material has already been known for a long time and has proved very successful. It goes without saying that, nevertheless, efforts are being made to improve these devices. In particular, attempts are made to improve the efficiency of fibre parallelization. Moreover, different fibres sometimes necessitate different processing methods.